In recent years, in the field of space development, attentions have been paid to a microsat (micro-miniaturized artificial satellite), which is monofunctional but can be developed easily, in addition to big and multi-functional artificial satellites. It is considered that easiness in the development of such microsat can reduce the cost per unit of an artificial satellite and also renders the space development more familiar. At present, a great number of microsats have been launched as piggyback satellites.
The merits of the microsat are the features of monofunctional and low cost. However, in order to provide the microsat with high performance, it is essential for the satellite to be equipped with three axial control mechanism. Because of that, an attitude observation system with high performance is required. However, considering the increase in the developmental cost for the satellite, it is not possible to use such a expensive hardware.
Conventionally, various types of sensors have been used as an attitude sensor for the three axial satellites. For example, it has been known that exact attitude estimation including rolls and yaws can be done by detecting an attitude angular velocity from a gyro, such as an inertia reference apparatus, and then integrating the attitude angular velocity. The inertia reference apparatus is an apparatus which is mounted with a rate gyro or the like in the three axial manner and packaged together. When directly integrating signals of the gyro and then using them, there is a merit for obtaining dynamical and good responsive detection. Then again, there is a demerit of accumulation of drifts during a long run. In order to compensate such accumulation of drifts, a manner of rendering feedback of the errors using a star tracker from the absolute reference to the detection system has been employed. However, because this manner requires expensive sensors, it is not possible to apply it to a microsat that is monofunctional and is required to be low cost.
The present invention was made for aiming at achieving the above-mentioned object, and it is an object of the present invention to provide an attitude estimation apparatus being provided with high accuracy and inexpensive and a method for estimating attitude, i.e., an attitude estimation apparatus using an inertia measuring apparatus and being capable of estimating the attitude of an artificial satellite by means of hardware, such as a piezoelectric vibration gyro and a fiber gyro, of which cost per unit is relatively low, and a method and a program for estimating the attitude.
With the present invention, it becomes possible to estimate the attitude only with information from the gyro without requiring sensors such as a star tracker. The conventional artificial satellites may face such a circumstance where they cannot use the sensors. For example, the present invention can be a countermeasure under a practical operation when an artificial satellite cannot use a sensor such as a star tracker in the maneuver.